diff options
| author | Willem de Bruijn <willemb@google.com> | 2017-08-10 12:29:19 -0400 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2017-11-06 15:14:22 +0100 |
| commit | cf9932e5076a92074c1ced41d4e6879003080175 (patch) | |
| tree | 064310b2a9f7b4083aa3818ccceaa227746f136f /net/ipv4/ip_output.c | |
| parent | c0cb0b8239214cabba1e6589bceae51770beae98 (diff) | |
udp: consistently apply ufo or fragmentation
commit 85f1bd9a7b5a79d5baa8bf44af19658f7bf77bfa upstream.
When iteratively building a UDP datagram with MSG_MORE and that
datagram exceeds MTU, consistently choose UFO or fragmentation.
Once skb_is_gso, always apply ufo. Conversely, once a datagram is
split across multiple skbs, do not consider ufo.
Sendpage already maintains the first invariant, only add the second.
IPv6 does not have a sendpage implementation to modify.
A gso skb must have a partial checksum, do not follow sk_no_check_tx
in udp_send_skb.
Found by syzkaller.
[gregkh - tweaks for 3.18 for ipv6, hopefully they are correct...]
[wt: s/skb_is_gso/skb_has_frags for 3.10]
Fixes: e89e9cf539a2 ("[IPv4/IPv6]: UFO Scatter-gather approach")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Conflicts:
net/ipv6/ip6_output.c
Diffstat (limited to 'net/ipv4/ip_output.c')
| -rw-r--r-- | net/ipv4/ip_output.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 650873c32..1204570dc 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -846,10 +846,12 @@ static int __ip_append_data(struct sock *sk, csummode = CHECKSUM_PARTIAL; cork->length += length; - if (((length > mtu) || (skb && skb_has_frags(skb))) && + if ((skb && skb_has_frags(skb)) || + ((length > mtu) && + (skb_queue_len(queue) <= 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && - (sk->sk_type == SOCK_DGRAM)) { + (sk->sk_type == SOCK_DGRAM))) { err = ip_ufo_append_data(sk, queue, getfrag, from, length, hh_len, fragheaderlen, transhdrlen, maxfraglen, flags); @@ -1160,6 +1162,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page, cork->length += size; if ((size + skb->len > mtu) && + (skb_queue_len(&sk->sk_write_queue) == 1) && (sk->sk_protocol == IPPROTO_UDP) && (rt->dst.dev->features & NETIF_F_UFO)) { skb_shinfo(skb)->gso_size = mtu - fragheaderlen; |